Ferrous Fumarate

Fructose-1,6-bisphosphate aldolase (FBA) stands as a pivotal enzyme involved within the Calvin cycle and glycolytic pathways in bacteria and higher plants, but the specific function of OsFBA in rice is still unclear. Here, we identified a chloroplast and mitochondria dual-localized FBA protein, OsFBA1, in rice. Experimental evidence showed that the functionally deficient osfba1 mutants featured a notable decline in chlorophyll content, photosynthetic rate, and severe growth impediment by the three-leaf stage, leading to eventual plant demise. Up-regulation of photosynthetic-pathway genes in the osfba1 mutants indicated the essential role of OsFBA1 in chloroplast development and suggested a compensatory mechanism of other genes in the process. Furthermore, the absence of OsFBA1 impaired the carbon assimilation in young rice seedlings, and supplying exogenous glucose could partially sustain the survival of osfba1 mutant for a few more days. Pathway-specific metabolomics analysis revealed a systemic change of metabolites in the glycolytic pathway, and consequential carbohydrates accumulation due to OsFBA1 disruption. Transcriptomics profiling corroborated the expression changes of photosynthesis, and carbon metabolism pathway genes. We further demonstrated that OsFBA1 serves as the primary FBA enzyme governing energy generation, photosynthesis and carbon metabolism. These results prove that OsFBA1 is an essential core gene in supporting the life cycle of rice, its expression has to be tightly regulated.

The jasmonate ZIM-domain (JAZ) proteins, known as inhibitors in the jasmonic acid (JA) pathway, have been reported to play a protective role against abiotic stress in plants. Nevertheless, the specific role of JAZ proteins in rice seedlings under alkaline stress remains unexplored. In this study, we mainly focus on OsJAZ10, investigating the physiological response mechanism and metabolic regulation on rice seedlings challenged by alkaline stress. Our results revealed that the antioxidant enzyme activity and osmotic adjustment ability of the OsJAZ10 overexpression lines were less affected by alkaline stress compared to WT (Wild-type) line. Metabolomic analysis demonstrated a significant accumulation of organic acids, including citrate and DL-malate, as well as amino acids such as DL-serine, DL-glutamine, threonine, glycine, and L-glutamate, in the OsJAZ10 overexpression plants in response to alkaline stress. Besides, OsJAZ10 was also involved in pantothenate and CoA biosynthesis, carbon fixation, and C5-branched dibasic acid metabolism in response to alkaline stress. Finally, OsJAZ10 was found to negatively regulated the biosynthesis and signaling of jasmonic acid pathway by repressing JA-responsive genes. Overall, this research elucidates the role of OsJAZ10 in conferring enhanced tolerance to alkaline stress in rice, providing valuable insights for the development of stress-tolerant rice varieties.